The present invention is related to a collapsible and deployable structure, and would be particularly useful for platforms that require hierarchy to achieve rigidity and strength requirements. More particularly, the present invention is a structure that can be collapsed from its deployed configuration into a linear configuration for storage or transportation.
It is often necessary to transport a structure that occupies considerable volume. Where a launch vehicle is being used to transport the structure, the problem of storage becomes acute because vehicles adapted for lifting a load from the earth's surface require a streamlined shape due to aerodynamic considerations. For example, unmanned launch vehicles ordinarily carry their payload in a fairing or tapered nose cone. Ordinarily, spacecraft structures such as antennas, sensing instruments and probes, and solar panels are collapsed to dimensions that will fit within the limited storage envelope of the launch vehicle, and are then unfurled or extended in space. It is thus a farther requirement that the collapsed structure be deployed without undue difficulty.
Structural hierarchy is the characteristic of a structure having similar geometry at decreasing length scales. For example, a truss where each strut is also a truss is known as a hierarchical structure. Structural hierarchy is desired because it reduces the material volume needed to achieve strength and stiffness requirements. In deployable structures, hierarchy also leads to more compact packaging because less material needs to be packaged.
The prior art has reduced the volume of collapsed structures by incorporating structural hierarchy in one dimension; however, the benefits of using structural hierarchy to collapse a deployable structure in two or all three dimensions has not been realized. There is a need in the art for a deployable structure that incorporates structural hierarchy to collapse in multiple dimensions, and thus realizes both the greater rigidity and stability per unit of cross-section area while in the deployed configuration, as well as the reduced volume in the collapsed configuration. The present invention fulfills this need in the art.